package com.hmdp.utils;


import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.format.annotation.DateTimeFormat;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;



@Component
public class RedisIdWorker {
    /**
     * 开始时间戳
     */
    private static final long BEGIN_TIMESTAP=1640995200L;
    /**
     * 序列号的位数
     */
    private static final int COUNT_BITS=32;

    private StringRedisTemplate stringRedisTemplate;

    private RedisIdWorker(StringRedisTemplate stringRedisTemplate){
        this.stringRedisTemplate = stringRedisTemplate;
    }

    public long nextId(String keyPrefix) {
        //生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSeconds=now.toEpochSecond(ZoneOffset.UTC);
        long timestamp=nowSeconds-BEGIN_TIMESTAP;
        //生成序列号
//获取当天的日期，精确到天
       String date= now.format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
        //自增长
        Long count=stringRedisTemplate.opsForValue().increment("icr:"+keyPrefix+":"+date);
        //拼接并返回
        return timestamp<<COUNT_BITS|count;
    }
}
